Electronic Telegram No. 3122
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET P/2012 K3 (GIBBS)
     A. R. Gibbs reports his discovery of a comet on CCD images taken with the
Mount Lemmon 1.5-m reflector (discovery observations tabulated below), the
object reported as having of fuzzy coma of size 9" x 7", elongated in p.a.
255 deg with an 8" tail on four co-added 30-s exposures taken in excellent
conditions; four co-added 60-s exposures taken soon afterwards (May 21.405-
21.408 UT) yielded a measurement for the elongation in p.a. 270 deg, with
Gibbs noting that it was hard to separate the tail from the coma in a crowded
star field.  After the object was posted on the Minor Planet Center's NEOCP
webpage, other CCD astrometrists have also commented on the cometary
appearance.  S. Foglia reports that twenty-seven stacked 60-s images taken by
R. Holmes (Ashmore, IL, USA; 0.61-m f/4 astrograph; May 22.3; measured by L.
Buzzi, H. Devore, S. Foglia, and T. Vorobjov) show a round coma up to 10" in
size.  H. Sato (Tokyo, Japan; remotely with a 0.43-m f/6.8 astrograph + f/4.5
focal reducer at the RAS Observatory near Mayhill, NM, U.S.A.; May 22.4) finds
a strongly condensed, round coma of diameter 20".  Erik Bryssinck (Kruibeke,
Belgium; remotely with a 0.43-m f/6.8 telescope near Nerpio, Spain; May 23.05)
finds the object to be diffuse with a diameter of about 8".  Four 180-s images
taken in good seeing with the 2.0-m "Faulkes Telescope North" at Haleakala on
May 23.4 by P. Miller, P. Roche, A. Tripp, R. Miles, R. Holmes, S. Foglia, and
L. Buzzi (measured by Buzzi and Foglia) show a clearly diffuse 7" wide coma,
elongated for at least 10" in p.a. 254 deg.  E. Guido, N. Howes, and G.
Sostero stacked eight R-band 60-s exposures obtained remotely using the 2.0-m
"Faulkes Telescope South" at Siding Spring on May 23.55 to find a 5" coma and
a tail nearly 5" long in p.a. 250 deg.

     2012 UT             R.A. (2000) Decl.       Mag.   Observer
     May  21.34553   17 16 41.78   - 4 11 41.6   18.3   Gibbs
          21.35133   17 16 41.60   - 4 11 41.2            "
          21.35715   17 16 41.40   - 4 11 41.2            "
          21.36301   17 16 41.19   - 4 11 40.7            "

The available astrometry, the following preliminary elliptical orbital
elements by G. V. Williams from observations spanning May 21-23, and an
ephemeris appear on MPEC 2012-K50.

     T = 2012 Sept. 3.5654 TT         Peri. = 158.5967
     e = 0.377613                     Node  = 128.1964  2000.0
     q = 2.160464 AU                  Incl. =  12.7642
       a =  3.471256 AU    n = 0.1523962    P =   6.47 years


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 May 23                      (CBET 3122)              Daniel W. E. Green